Hi Matt,
You are completely right, which is why I qualified conditions after
saying it was a good idea. You have to remove hundreds of variables to
justify the eye-dropper testing method, however if you have a bird in
the field that is part of a group, you should be able to compare
colour points on those individuals providing it is a high quality
image, and it was something I had never considered before.
Best for now
Brian

On 5/15/13, Clive Mann <clivefmann@gmail.com> wrote:
> Rosemary,
>
> Most species of bird show very little (almost none to our eyes) variation
> except for age/sex/breeding plumage/wear, or geographical variation which
> may be distinguished as a separate subspecies. A small number e.g. many *
> Buteo*/*Pernis*, do show considerable individual variation. There is also
> the problem of abnormalities such as albinism, leucism etc. etc.
> When an individual such as Brian's pipit shows a plumage variation that is
> outside the above then birders get 'fussed'.
>
> Clive Mann
>
> On 15 May 2013 07:38, Robrien.dolan <robrien.dolan@gmail.com> wrote:
>
>> As a new birder and an old geneticist, may I enquire why birders get so
>> fussed about genetic variation within species?
>>
>> Rosemary
>>
>> Sent from my iPad so please excuse typos
>>
>> Dr Rosemary B Dolan
>> P O Box 24437
>> Karen 00502
>> Nairobi
>> +254.733744311
>> Email: robrien.dolan@gmail.com
>>
>>
>> On 14 May 2013, at 17:50, Clive Mann <clivefmann@gmail.com> wrote:
>>
>>
>>
>> Brian,
>>
>> When I first became seriously interested in birds in 1950s there were
>> birds that could not be identified - they were called 'hoodwinks'.
>> However,
>> hubris has ruled, and we expect to be able to identify everything. Your
>> pipit is a reminder that hoodwinks still exist.
>>
>> Clive
>>
>> On 14 May 2013 13:30, Brian Finch <birdfinch@gmail.com> wrote:
>>
>>> **
>>>
>>>
>>> Dear All,
>>>
>>> Many, many thanks to all those who contributed to find an identity for
>>> the strange green Tree Pipit seen on the Ngong Hills, alongside a
>>> normal Tree Pipit.
>>>
>>> I have attached the thread of correspondence showing peoples arguments
>>> for and against the identity of the bird being an Olive-backed Pipit
>>> or Tree Pipit.
>>>
>>> It makes for a very interesting and educational read, and the final
>>> conclusion is that this was a very, very strange bird, and specific
>>> identity will always be a mystery.
>>>
>>> What I have personally learnt is; if there are two rarities around at
>>> the same time, make sure each receives fair attention! A green Tree
>>> Pipit might be just a green Tree Pipit. Not everything seen can be
>>> labelled (certainly something that I have already learnt from not
>>> being able to identify many Aquila Eagles). All Tree Pipits in future
>>> will require more than a casual glance. Olive-backed Pipit is not an
>>> impossibility to appear in East Africa one day. That there are
>>> instances of wild hybridisation of Pipits, including three involving
>>> Tree Pipits (see attached details). That Killian’s method of colour
>>> sampling on the computer using the photo programmes eye-dropper tool
>>> is a brilliant idea, (providing the images were taken with identical
>>> settings etc). Finally I really don’t want to see an identical bird to
>>> this one again!
>>>
>>> Again many thanks for this educative trail,
>>> Brian
>>>
>>
>>
>>
>> --
>> Dr C F Mann
>>
>>  
>>
>>
>
>
> --
> Dr C F Mann
>